JPS59219724A - Electrochromic display device - Google Patents

Abstract

PURPOSE:To provide diversity of display by using a mixture composed of an oxidation type EC material and a redution type EC material having different coloring hues as an electrochromic (EC) materal, providing an insulating film in the region except the display pattern of a display electrode and providing a counter electrode in the position shaded by the same. CONSTITUTION:A mixture composed of an oxidation coloring type (O type) EC material and reduction coloring type (R type) EC material having coloring hues different from each other are used for the EC material to be used for an electrolyte 14. A display electrode 11 is provided on one transparent base plate 9 and an insulating film 13 is provided in the region except the pattern to be displayed on the electrode 11. A counter electrode 12 is formed in the position shaded by the film 13 when viewed from the base plate 9 side provided with the electrode 11. A voltage is impressed on the electrodes 11, 12 with the ECD of such constitution. When a positive voltage is impressed thereon, the O type EC material forms a display color and when a negative voltage is impressed thereon, the R type EC material forms a display color. The color formed on the electrode 12 in this stage does not exist in the display pattern region and is therefore not visually sensed. When the impressed voltage is made 0V, the display is erased. The diversity of the display is remarkably improved by using the plural EC materials.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrochromic display device (hereinafter referred to as ECD).
). Among these, it particularly relates to a variable color ECD that can display multiple colors in one segment.

One ECI related to the present invention is a dissolution-diffusion type that applies the phenomenon in which an electrochromic material (EC material) called an electrochromic material reversely colors and fades due to an oxidation-reduction reaction based on an electrode reaction. It is ECD. Recently, ECDs have been attracting attention because they can operate at low voltages and low power and provide bright and clear displays.

The structure of a typical conventional dissolving type ECD is shown in FIG. Generally, such an ECD has two parts: a display substrate 1 and a counter substrate 2.
The two substrates are assembled via a spacer 7, and a sealing material 8
It is produced by injecting electrolyte 6 into a cell that has been sealed. In this type of ECD, in order to obtain a white background, an original reflector plate is placed between the inner substrates, or an electrolyte liquid is mixed with a white powder to form a paste. The original reflecting plate is made of ceramic or polymer such as alumina, and the white powder is titanium oxide, alumina, etc. powder. Hereinafter, in this specification, these objects will be collectively referred to as the original reflector.

The display substrate 1 is generally a transparent substrate made of glass, plastic, or the like. A transparent electrode 3 is provided on this. This is a tin oxide (S n02 ) film, an indium oxide/tin oxide (ITO) film, etc., and is usually formed by a vacuum evaporation method, but chemical methods such as a spray method may also be used. There are various structures for the counter substrate 2 and the counter electrode 4. Typical examples include those in which a transparent electrode is formed on a glass substrate, those in which a metal film is formed on a glass substrate, and those in which a metal film is formed on a glass substrate. There are a press of a carbon mixture placed on a glass substrate, a metal plate 1, and the like.

There are several divine methods that can be used to display all of the nine characters, but one method is to use a surface mask 5 so that only the patterned segments to be displayed are exposed to the electrolyte. This is a method of providing The material for the surface mask is mainly white ink in which white powder is dispersed in resin, and it is formed by screen printing. Furthermore, when displaying each segment separately, it is necessary to divide the display electrodes to which these segments are attached accordingly. Note that although a surface mask 5 is depicted in the figure, this is not essential.

As generally stated, the electrolyte 4 contains a solvent, a support 1, an electrolyte,
It is composed of three components of EC material. Any solvent can be used as long as it is highly polar and stable; in addition to water,
Nonaqueous solvents such as globylene carbonate and dimethylformamide are used.

The case where a non-aqueous solvent is used will be mainly described below.

For the supporting electrolyte, ordinary inorganic salts are used for water, but for non-aqueous MmK, alkali metals or tetraalkylammonium and halogens, perchloric acid ccO4, fluoroborey) BF4. Fluorophosphiny) PF
, salt is used. EC materials include Na2WO4, C
Inorganic materials such as transition metal compound salts 1 such as aWO4, BaWO4, Na2M604, aromatic or heterocyclic compounds such as viologen, tetrathiafulvalene, pyrazoline, fluorene, anthraquinone, pyrylium, pyridium, methylene blue, and organic compounds such as derivatives thereof. There are organic metal materials such as ferroin and ferrocene.

A conventional dissolving type ECD having such a structure can display only one color. For example, the initial state of ECD using butyl anthraquinone as the EC material is white, and when a negative voltage is applied to the transparent electrode, the color develops to red, and when a reverse voltage is applied, the color disappears and returns to white. This white color is the color of the light scatterer.

Not only dissolvable ECDKs but also ECDs that have been announced so far.
Most of them display only one color.

As an ECD that produces multiple colors, one is known that has a structure in which a vapor-deposited film of a complex of a lanthanoid metal and shiftalodianine is formed on a transparent electrode. This type can display three colors (red, green, and stomach) by changing the applied voltage, but there is no state where it becomes colorless and transparent, or white, and the display colors are limited, making it possible to diversify. It has disadvantages such as lack of sex.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrochromic display device which eliminates the above-mentioned drawbacks and has a high display diversity, that is, can display multiple colors in one segment.

The display device according to the present invention is an electrochromic display device comprising a pair of transparent substrates each having a display electrode, at least one of which is a transparent electrode, and filled with an electrolytic solution in which an electrochromic material and a supporting material are dissolved. , the electrochromic material is a mixture of an oxidation color-forming electrochromic material and a reduction color-forming electrochromic material having different coloring hues, a display electrode is provided on one transparent substrate, and a pattern other than the pattern to be displayed on the display electrode is provided. The device is characterized in that an insulating film is provided in the area, and a counter electrode is formed at a position hidden behind the insulating film when viewed from the transparent substrate side with the display electrode φh1 apart.

A schematic cross-sectional view of an embodiment of the display device according to the present invention is shown in FIG.
As shown in the figure. On the display substrate 9, a display pole 11 made of a transparent electrode is formed. A surface mask 13 made of a transparent or white insulating film is formed on the display electrodes other than the pattern to be displayed. Alternatively, a white insulating film may be formed on the display substrate 9 in advance in an area other than the pattern to be displayed, and then the display electrodes 11 may be formed, but any structure may be used.

Next, a counter electrode 12 is formed on the surface mask 13, and this structure is one of the features. Between the pair of substrates is an electrolytic solution 14 containing an oxidation coloring type (0 type) EC material and a reduction coloring type (R type) EC material having different coloring hues and a supporting salt.
This is another feature of this device. Here, the O-type EC material is an EC material that is nearly colorless in a neutral state and develops color upon oxidation. R type EC
The wood is also nearly colorless in its neutral state;
It is an EC material that develops a rich color depending on the reducing source. The display substrate, the display electrode of the counter substrate 9, the surface mask of the counter electrode 1, etc. used in this device can be formed using the same materials and manufacturing methods as those of the conventional device.

The ECD according to the present invention includes a display electrode 11, a counter electrode, 12
When a voltage is applied from the outside, the 0-type EC material develops color at the electrode to which a positive voltage is applied, and the R-type EC material develops color to the electrode to which a negative voltage is applied. Since the counter electrode 12 is not located under the surface mask 13, at least in the area corresponding to the pattern to be displayed, the color development on the counter electrode is not visible.

Therefore, when a full positive voltage is applied to the display electrode with respect to the counter electrode, the coloring hue of the 0-type EC material becomes the displayed color, and when a negative voltage is applied, the coloring hue of the R-type EC material becomes the displayed color. .

When the applied voltage is set to Ov, the colored 0 type and R type EC materials react with each other, returning to a neutral colorless state and the display disappears.

Melting type ECD using both 0 type EC material and R type EC material as EC material is disclosed in Japanese Patent Application No. 145767-1988 (9%).
In these known devices, the counter electrode is formed in a region of the display electrode that faces the pattern to be displayed. As already mentioned, when the 0 type EC material develops color at either the display electrode 11 or the counter electrode 12, the R type EC material develops color at the other electrode. This is due to Faraday's law, which states that since current flows between paired electrodes in the rust solution, K requires the same amount of electrode reaction to occur on the valley and valley electrodes. Therefore, in the conventional device in which the counter electrode is formed in the area of the display electrode that faces the pattern to be displayed, it is not possible to see the colors of the O-type EC material and the R-type EC material independently, and the mixed color of the two colors cannot be seen independently. Only a negative color can be displayed, and this has no relation to the polarity of the applied HL pressure. Therefore, it is impossible to change the display color by changing the polarity of the applied voltage in one and the same segment as in the present invention, and it is considered that the present invention is advantageous.

The O type EC material and the R type EC material used in the present invention are not limited to one type each, and a plurality of types of EC materials can be used for the O type or R type or both the O type and R type.

Such a mixture can be used to display a mixed color kff of the coloring hue of each EC material alone, thereby significantly increasing the variety of displays.

The present invention will be described below based on examples.

Example 1 In FIG. 2, the display substrate 9. The counter substrate 10 is a glass plate with f9, and the display electrode 11 is a tin oxide/indium oxide (ITO) electrode formed by vacuum evaporation and processed into a desired pattern by chemical etching. Next, a surface mask 13 made of epoxy resin containing titanium oxide alloy
was screen printed on the area other than the pattern to be displayed on the top of the display 1. Furthermore, as the counter electrode 12, tin oxide
An indium oxide (ITO) electrode was vacuum deposited only on the surface mask 13. The gap between both plates 9.10 is 30-1
It was adjusted to about 00μ and sealed with an epoxy thread adhesive. Ugly liquid 14 contains 1-p-methoxyphenyl-3-p-diethylaminostyryl-5-diethylaminophenyl-Δ2-pyrazoline (0,1-0
．． 3 mol/l) and 2-t-butylanthraquinone (0.1 to 0.3 mol/l) as the R-type EC material.

Tetrapterammonium fluoroborade (0.05 to 0.2 mol/l) and tetrabutylammonium iodide (0.05 to 0.2 mol/l) were used as supporting electrolytes.
l/l) using N-2-methyl-pyrrolidinone as the solvent.

The initial state of this ECD is yellowish white or colorless. When a negative voltage of -2.OV is applied to the display electrode with respect to the counter electrode, a red display with a contrast of 2:1 is obtained in a response time of 0.5 seconds, and by setting the contrast to OV, the display disappears in about 2 seconds. color and returned to the initial stage. Plus +2. By applying a positive voltage of OV, a blue display with a contrast of 3:1 was obtained in about 9.0.5 seconds. When I set it to OV, the color disappeared in a 2 second response time and returned to its initial state.

As described above, the ECD according to this embodiment is a two-color display ECD of red and blue.

Example 2 Example 1 except that 1,3.5-)su(p-methoxyphenyl)-Δ2-pyrazoline was used as the type 0 EC material.
The 0 ECD with the same material and structure as 0 is a two-color display ECD that displays red when a negative voltage is applied and displays yellow-green when a positive voltage is applied. Other display performance is almost the same as in Example 1.

Example 3 An ECD with the same materials and structure as in Example 1 except that dimethylformamide was used as a solvent is a two-color display ECD that displays red when a negative voltage is applied and displays blue when a positive voltage is applied. Other display performance is almost the same as in Example 1.

Example 4 Benzo[α]anthracene-7゜12 as R-type EC material
The ECD having the same materials and structure as in Example 1 except for using -dione is a two-color display ECD that displays green when a negative voltage is applied and displays blue when a positive voltage is applied. Other display performance is Example 1
It is similar to

Example 5 0ECD has the same materials and structure as Example 1 except that chloronaphthoquinone was used as the R-type EC material. 0ECD displays yellow when a negative voltage is applied and displays blue when a positive voltage is applied. Other display performance is almost the same as in Example 1.

Example 6 Tetrathiafulvalene was used as the 0-type EC material, and 2-t-butylanthraquinone (0.1 m
The ECD, which had the same material and structure as Example 1 except for using benzo[α]anthracene-7°12-dione (0.1 mol/l), showed a brown color when a negative voltage was applied, and a positive The display is blue when voltage is applied. Other display performance is almost the same as in Example 1.

A schematic cross-sectional view of another embodiment of a display device according to the invention is shown in FIG. A display electrode 11 made of a transparent electrode is formed on the display substrate 9. A surface mask 13 made of a transparent or white insulating film is formed on the display electrodes other than the pattern to be displayed. Alternatively, a white insulating film may be formed on the display substrate '&9 in advance in an area other than the pattern to be displayed, and then the display electrode 11 may be formed, but any structure may be used.

A counter electrode 12 formed by pressing a mixture of a transition metal lead such as an iron complex and carbon is inserted onto the wire, and this structure is one of the features of this embodiment.

This structure allows the use of carbon thread electrodes with small potential fluctuations, so the display does not fluctuate over time and a stable display can be obtained. It also has the advantage of being easy and inexpensive to manufacture. Between the pair of substrates are an oxidation coloring type (O type) EC material and a reduction coloring type (R type) EC material having different coloring hues.
Another feature of this device is that an electrolytic solution 14 containing a material and a supporting salt is sealed.

Embodiment 7 In FIG. 3, the display substrate 9. The counter substrate 10 was a glass plate, and the display electrode 11 was a tin oxide/indium oxide (ITO) electrode, which was formed by vacuum etching, and an FMW pattern was formed by chemical etching. Next, a surface mask 13 made of epoxy resin containing titanium oxide
was screen printed on the area other than the pattern to be displayed on the display panel.

A counter electrode 12, which was made entirely of carbon and iron filling and was pressed onto a titanium mesh wire, was inserted into the singing area of the double plate other than the pattern to be displayed. The distance between the difference plates 9° and 10 is 30
It was sealed with epoxy thread adhesive. Dentakugan 14 has 1-p as 0 type EC material.
-methoxyphenyl-3-p-diethylaminestyryl-5-diethylaminephenyl-Δ2-pyrazoline (0
, 1-0.3 mol/l).

2-t-butyl 7-anthraquinone (0,
1-0.3 mol/A), tetrabutylammonium fluoroborey) (0.05-0
．． 2 mol/7) and tetrabutylammonium iodide (0.05 to 0.2 mol/l), and N-2-menal-pyrrolidinone was used as a solvent.

The initial state of this ECD is yellowish white or colorless.

When a negative pressure of -2.0V is applied to the display ° electrode with respect to the opposite north pole, a red display with a contrast of 2:1 is obtained with a response time of 0.5~, and by setting it to 0■, The color faded in seconds and returned to its initial state. Plus +2. By applying a positive voltage of Ov,
A blue display color with a contrast of 3:1 was obtained in about 9.0.5 seconds. By setting it to Ov, the color disappeared in a response time of 2 seconds and returned to the initial state.

As described above, the ECD according to this embodiment is a two-color display ECD of red and blue.

Example 8 Except for using 1.3.5-tri(p-methoxyphenyl)-Δ2-pyrazoline as the 0-type EC material, 0ECD, which has the same material and structure as the actual side stone, displays a red shade when a negative voltage is applied. , is a two-color display ECD that displays yellow-green when a positive voltage is applied. The other display properties are almost the same as in Example X.

Example 9 Except that dimethylformamide was used as the solvent,
The ECD having the same material and structure as in Example 7 is a two-color display ECD that displays red when a negative voltage is applied and displays blue when a positive pressure is applied. Other display performance is almost the same as in Example 1.

Example 10 Benzo[α]anthracene-7゜12 as R-type EC material
The ECD, which has the same materials and structure as those in the example except that dione was used, is a two-color display ECD that displays green when a negative voltage is applied and displays blue when a positive voltage is applied. Other display performance is Example 1
It is similar to

Example 11 Same material and structure as Example C except that chloronaphthoquinone was used as the R-type EC material. ECD is negative.

Example 12 Tetrathiafulvalene was used as the 0-type EC material, and 2-t-butylanthraquinone (0,1
mol/7) and benzo[α]anthracene-7° are displayed in brown color, and when a positive voltage is applied, the display is blue. Other display performance is almost the same as in Example I.

A schematic cross-sectional view of yet another embodiment of the display device according to the present invention is shown in FIG. A display electrode 11 made of a transparent electrode is formed on the display substrate 9.

A surface mask 13 made of a transparent or white insulating film is formed on the display electrodes other than the pattern to be displayed. Alternatively, a white insulating film is formed on the display substrate 9 in advance in areas other than the pattern to be displayed, and then the display electrodes 1
1 may be formed, but any structure may be used. On the other hand, a counter electrode 12 is formed in a region of the display electrode on the counter substrate 10 that is opposite to a region other than the pattern to be displayed, and this structure is one of the features of this embodiment. Similar to the first embodiment described above, this structure allows thinning of the display device by reducing the thickness of the film. Also, since electrodes can be created by vapor deposition, they have the advantage of being easy to manufacture, cheap, and reliable.
Ru. Between the pair of substrates, an electrolytic solution 14 containing an oxidation coloring type (0 type) EC material and a reduction coloring type (R type) EC material having different coloring hues and a supporting salt is sealed. This is a feature of this device.

Example 13 In FIG. 4, the display substrate 9. Both of the counter substrates 10 are glass plates, and the display electrodes 11. Opposing electrodes 't & 12 are both tin oxide/indium oxide (ITO) electrodes, which are formed by vacuum evaporation and processed into a desired pattern by chemical etching. Next, a surface mask 13 made of an epoxy resin containing titanium oxide was screen printed on the display electrode in an area other than the pattern to be displayed. Inner board 9, 10
The spacing was adjusted to about 30 to 100 microns, and sealed with an epoxy adhesive. 't# liquid 14 contains 1-p-methoxyphenyl-3-p-diethylaminostyryl-diethylaminophenyl-Δ2-pyrazoline (0.1 to 0.3 mol/A') as a type 0 EC material, and type R EC. 2-t-butylanthraquinone (0.1-0.3
mol/l) + support 1! Tetrabutylammonium fluoroborate (0.05-0.2 mol/l
).

and tetrabutylammonium iodide (0,05
~0.2 mol/l) mixture, 11-2- as solvent
Methyl-pyrrolidinone was used.

The initial 4υ” state of this ECD is yellowish-white or colorless. When a negative voltage of -2.0V is applied to the display electrodes for the opposite camera, the contrast is 2 with a response time of 0.5 seconds.
A red display of 1 was obtained, and by turning the display to Ov, the color disappeared in about 2 seconds and returned to the initial state. Plus +2. By applying a positive voltage of Ov, a blue display color with a contrast of 3:1 was obtained in about 0.5 seconds. By setting it to Ov, the color disappeared in a response time of 2 seconds and returned to the initial state. As described above, the ECD according to this embodiment is a two-color display ECD of red and blue.

Example 14 0ECD has the same materials and structure as Example 1, except that 1.3.5-)su(p-methoxy'diphenyl)-Δ2-pyrazoline was used as the 0-type EC material. It is a two-color/θ display ECD with a red front thread when pressure is applied and a yellow-green display when a positive pressure is applied.・Other display performance is actual) JI!
J Setaru and Q”1 are the same.

Example 15 Red display when negative voltage is applied, blue display when positive voltage is applied 7
．． 3 Common in two-color display ECD. Other display performance is almost the same as the implementation ψu.

Example 16 Same as ψ1j and 1j except that 12-on was used.

Materials and structures 0ECD are shown in green with negative pressure stamp u.
C + positive voltage sign - blue display at the mouth, two-color display ECD. (/9 of Ikl The display performance is the same as that of the implementation side control.

Example R21 Using chloronaphthoquinone as the EC material/
J The ECD, which has the same materials and structure as the implemented Rerike, is the /e ECD which displays yellow when a negative voltage is applied and blue when a positive voltage is applied. Other display performance is almost the same as Example ←
There is cl.

Example 18 Tetrathiafulvalene was used as the 0-type EC material, and 2-t-butylanthraquinone (0.1 m
ol/l) and benzo[α]anthracene-7° or Kuhi, and a blue color is displayed when a positive voltage is applied. The display performance of the other /d is almost the same as that of Example 1.

As in the above embodiments, instead of using one type of EC material for either or both of the EC material and the R-type EC material having various display color pairs, multiple EC materials are used. By using a mixed color of these EC materials as the display color, it is also possible to diversify the display colors.

The O-type EC material and ftmEc material used in the present invention are not limited to the EC materials described in the examples, and various EC materials that develop color upon oxidation or reduction may be used. Such various O
By using the type EC material and the R type EC material in the ECD of the present invention, various two-color displays can be realized.

[Brief explanation of the drawing]

FIG. 1 is a schematic top view of the interior of an example of a conventional ECD. 4 to 4 are schematic cross-sectional views showing the configuration of an embodiment of the present invention. In the figures, 9...display substrate 10...counter substrate 11...
・Display electrode 12...Opposing anode 13...
Surface mask 14... Electrolyte taper fP Physician Internally employed 5. I- Figure 1 4 z Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] An electrochromic display device comprising a pair of substrates, at least one of which is transparent, filled with an electrolytic solution in which an electrochromic material and a supporting electrolyte are dissolved,
A mixture of an oxidation color-forming electrochromic material and a reduction color-forming electrochromic material having different coloring hues is used as the electrochromic material, a display electrode is provided on a transparent substrate on the -0 side, and a pattern to be displayed on the display electrode is used. An electrochromic display device characterized in that an insulating film is provided in the other areas, and a counter electrode is provided at a position hidden behind the insulating film when viewed from the side of a transparent substrate provided with display electrodes.